https://gcc.gnu.org/bugzilla/show_bug.cgi?id=46921
--- Comment #5 from Joseph S. Myers <jsm28 at gcc dot gnu.org> --- Author: jsm28 Date: Tue Mar 13 18:10:09 2018 New Revision: 258497 URL: https://gcc.gnu.org/viewcvs?rev=258497&root=gcc&view=rev Log: PR c/46921 Lost side effect when struct initializer expression uses comma operator This patch fixes improper handling of comma operator expression in a struct field initializer as described in: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=46921 Currently, function output_init_element () does not evaluate the left hand expression in a comma operator that's used for a struct initializer field if the right hand side is zero-sized. However, the left hand expression must be evaluated if it's found to have side effects (for example, a function call). Patch was successfully bootstrapped and tested on x86_64-linux. gcc/c: 2018-03-13 David Pagan <dave.pa...@oracle.com> PR c/46921 * c-typeck.c (output_init_element): Ensure field initializer expression is always evaluated if there are side effects. gcc/testsuite: 2018-03-13 David Pagan <dave.pa...@oracle.com> PR c/46921 * gcc.dg/pr46921.c: New test. Added: trunk/gcc/testsuite/gcc.dg/pr46921.c Modified: trunk/gcc/c/ChangeLog trunk/gcc/c/c-typeck.c trunk/gcc/testsuite/ChangeLog